Microwave plasma torch generator and system

Abstract

The invention belongs to the field of plasmas, and particularly relates to a microwave plasma torch generator which comprises a microwave coaxial structure and a plasma torch generating structure, and the plasma torch generating structure is installed at the end of the microwave coaxial structure. The plasma torch generation structure comprises an airflow outlet, the airflow outlet is a penetrating opening, sawteeth are arranged on the inner wall of the airflow outlet, the microwave coaxial structure comprises an inner conductor and an outer conductor, the inner conductor is arranged in the outer conductor, an airflow channel is arranged between the inner conductor and the outer conductor, and the airflow channel is communicated with the airflow outlet. And the airflow channel is communicated with the airflow outlet. The invention provides a microwave plasma torch generator and system, and aims to generate a microwave plasma torch with uniform width.

Description

Technical Field

[0001] This invention belongs to the field of plasma, specifically relating to a microwave plasma torch generator and system. Background Technology

[0002] Plasma technology, as a highly efficient surface treatment and material modification technique, has been widely applied in several key industrial fields such as semiconductor manufacturing, material surface modification, environmental protection, and thin film deposition due to its high energy, cleanliness, and controllability. As industrial production continues to advance towards large-scale and refined operations, the demand for large-area, highly uniform, wide-span plasma processing is becoming increasingly urgent, placing extremely high demands on the lateral dimensions, density uniformity, and stability of plasma torches. Currently, the mainstream technologies used in industry to generate plasma are radio frequency discharge and microwave discharge.

[0003] However, existing microwave wide-band plasma sources and conventional radio frequency plasma sources both have insurmountable technical defects in practical applications, which cannot meet the industrial production requirements for wide-band, uniform plasma, as follows: Existing radio frequency discharge plasma sources have two major drawbacks in application: First, they are prone to electrode sputtering, which contaminates the plasma and the surface of the workpiece, seriously affecting product quality. Second, they are prone to standing wave effects during radio frequency discharge, which leads to uneven distribution of plasma energy, resulting in local differences in the density and intensity of the plasma torch, making it impossible to achieve large-area uniform processing.

[0004] Existing wide-band microwave plasma sources mainly employ two design schemes: array-type structure and slotted waveguide structure. For array-type wide-band microwave sources, wide-band coverage is achieved by arranging multiple microwave discharge units in an array. However, strong electromagnetic interference is generated between adjacent units, leading to problems such as irregular plasma torch shape and uneven intensity distribution. For slotted waveguide-type wide-band microwave sources, microwave energy attenuates along the waveguide slot during transmission, resulting in a gradient distribution of output field strength at different locations on the waveguide. The field strength is stronger in the region near the microwave input end and weaker in the region far from the input end.

[0005] In summary, there is an urgent need in the existing technology for a device that can achieve a wide-range uniform microwave plasma torch. Summary of the Invention

[0006] The present invention provides a microwave plasma torch generator and system, the purpose of which is to generate a wide-width, uniform microwave plasma torch.

[0007] To achieve the above objectives, the present invention provides a microwave plasma torch generator, comprising a microwave coaxial structure and a plasma torch generating structure, wherein the plasma torch generating structure is mounted at the end of the microwave coaxial structure. The plasma torch generating structure has an airflow outlet, and the inner walls on opposite sides of the airflow outlet are serrated. The microwave coaxial structure includes an inner conductor and an outer conductor, with the inner conductor disposed inside the outer conductor. An airflow channel is formed between the inner conductor and the outer conductor, and the airflow channel is in communication with the airflow outlet.

[0008] Preferably, the airflow outlet includes an inner side and an outer side, the inner side of the airflow outlet is adapted to the airflow channel, and the outer side of the airflow outlet faces outward; along the direction from the inner side to the outer side of the airflow outlet, the protrusion height of the serrations gradually increases and / or the width of the serrations gradually increases.

[0009] Preferably, the length and width of the saw teeth are 1.5 mm. 0.5mm.

[0010] Alternatively, the length and width of the saw teeth are 2mm. 1mm.

[0011] Preferably, the serrations are provided on the long sidewall of the airflow outlet.

[0012] The extension length of the saw teeth is the same as the length of the airflow outlet.

[0013] The extension width of the serrations is the same as the width of the sidewall of the airflow outlet.

[0014] The serrations shown are evenly distributed on the sidewall of the airflow outlet.

[0015] Preferably, the outer conductor is provided with an airflow inlet, which is connected to the airflow channel between the inner conductor and the outer conductor.

[0016] Preferably, the airflow inlets are located on both sidewalls of the outer conductor.

[0017] Preferably, the inner conductor includes a connector end and a working end, the connector end has a circular cross-section, the working end has a rectangular cross-section, and the working end is configured to correspond to the plasma torch generating structure.

[0018] Preferably, the inner conductor extends into the airflow outlet.

[0019] The microwave coaxial structure and the plasma torch generating structure are detachably connected.

[0020] The second aspect of the present invention discloses a microwave plasma torch generating system, including a microwave source, a gas source, and a microwave plasma torch generator, wherein the microwave source and the gas source are both connected to the microwave plasma torch generator.

[0021] Preferably, the device further includes an impedance matching device, through which the microwave source is connected to the plasma torch generating device.

[0022] It also includes a gas flow control unit, through which the gas source is connected to the microwave plasma torch generator.

[0023] The beneficial effects of this invention are as follows: the microwave coaxial structure and the plasma torch generating structure work together. When microwave energy is transmitted to the plasma torch generating structure, the geometric characteristics of the serrated tips enhance the local electric field, thereby effectively breaking down the gas under normal pressure. Simultaneously, the gaps between adjacent tips form a transverse energy enhancement region through electromagnetic coupling, inducing the plasma to remain uniform in the transverse width direction, suppressing the filamentary discharge phenomenon in normal pressure discharge, thus obtaining a wide-area sheet-like plasma torch with high uniformity. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a microwave plasma torch generator.

[0025] Figure 2 This is a schematic diagram of the plasma torch generating structure.

[0026] Figure 3 This is a cross-sectional view of the plasma torch generating structure.

[0027] Figure 4 This is a schematic diagram of the electric field distribution at the sawtooth location in Example 1.

[0028] Figure 5 This is a schematic diagram of the airflow field distribution at the sawtooth area in Example 1.

[0029] Figure 6 This is a schematic diagram of a microwave coaxial structure.

[0030] Figure 7 This is a schematic diagram of airflow inside the device.

[0031] Figure 8 This is a schematic diagram of the inner conductor.

[0032] Figure 9 This is a schematic diagram of the electric field distribution at the sawtooth location in Example 2.

[0033] Figure 10 This is a schematic diagram of the airflow field distribution at the sawtooth section in Example 2.

[0034] Figure 11 This is a schematic diagram of the electric field distribution and airflow field distribution at the sawtooth location in Comparative Example 1.

[0035] Figure 12 This is a schematic diagram of the electric field distribution and airflow distribution at the sawtooth location in Comparative Example 2.

[0036] Figure 13 This is a schematic diagram of the electric field distribution and airflow field distribution at the sawtooth location in Comparative Example 3.

[0037] Figure 14 This is a schematic diagram of the electric field distribution and airflow distribution at the sawtooth points in Comparative Example 4.

[0038] Figure 15 This is a schematic diagram of the electric field distribution and airflow field distribution at the sawtooth location in Comparative Example 5.

[0039] Figure 16 This is a schematic diagram of the electric field distribution and airflow field distribution at the sawtooth location in Comparative Example 6.

[0040] Figure 17 This is a schematic diagram of the electric field distribution and airflow field distribution at the sawtooth location in Comparative Example 7.

[0041] Figure 18 This is a schematic diagram of the electric field distribution and airflow field distribution at the sawtooth location in Comparative Example 8.

[0042] The reference numerals in the attached figures include: plasma torch generating structure 1, gas outlet 11, sawtooth 12, microwave coaxial structure 2, inner conductor 21, connector end 211, working end 212, outer conductor 22, connector 23, and gas inlet 24. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention.

[0044] The basic implementation examples are as follows: Figure 1 As shown, a microwave plasma torch generator is designed to generate a wide and uniform microwave plasma torch, and can meet the needs of surface modification, cleaning or thin film deposition of large-area substrate materials under different atmospheric pressure environments.

[0045] like Figure 1 and Figure 2As shown, the plasma torch generating device in this embodiment specifically includes a microwave coaxial structure 2 and a plasma torch generating structure 1. The plasma torch generating structure 1 is precisely installed at the end of the microwave coaxial structure 2, and the plasma torch generating structure 1 is generally rectangular. The center of the plasma torch generating structure 1 has a through-hole gas outlet 11, which is designed as a rectangular opening, preferably a rectangular opening. Simultaneously, evenly distributed serrations 12 are uniformly arranged on the inner wall of the gas outlet 11. The serrations 12 are preferably located on the inner walls of the long sides of the gas outlet 11; the width of the serrations 12 is designed to be consistent with the length of the inner walls of the long sides of the gas outlet 11, thereby ensuring that the serrations 12 can cover the entire long side area; the length of the serrations 12 is also consistent with the length of the gas outlet 11, so that the longitudinal extension length of the serrations 12 matches the size of the gas outlet 11. In this embodiment, the length (H) and width (L) of the outer side of the serrations 12 are 1.5 mm. 0.5mm.

[0046] When microwave energy is transmitted to the plasma torch generating structure 1, the geometric characteristics of the serrated tips 12 enhance the local electric field, thereby effectively breaking down the gas under normal pressure. Simultaneously, the gaps between adjacent tips form a transverse energy enhancement region through electromagnetic coupling, inducing the plasma to remain uniform in the transverse width direction, suppressing the filamentary discharge phenomenon in normal pressure discharge, and thus obtaining a highly uniform, wide-area sheet plasma. Figure 4 As shown.

[0047] It should be noted that if the serrations 12 are only provided on one side of the inner wall of the gas outlet 11, the electric field intensity distribution on both sides of the gas outlet 11 will be uneven, and the gas flow velocity will be asymmetrical. This will significantly reduce the working stability of the plasma torch. Therefore, in this embodiment, by symmetrically providing the serrations 12 on the inner walls of both sides of the gas outlet 11, the electric field and gas flow conditions on both sides can be effectively balanced, significantly improving the overall stability of the plasma torch. Figure 5 As shown.

[0048] It is understandable that: Figure 3 As shown, in this embodiment, for better plasma torch generation, the width of the serration 12 is preferably designed to be exactly the same as the length of the long side inner wall of the gas outlet 11, while the length of the serration 12 is the same as the length of the gas outlet 11. However, in some other embodiments, the width of the serration 12 can also be set to be less than the length of the long side inner wall of the gas outlet 11, and the length of the serration 12 can also be set to be less than the length of the gas outlet 11. Even the serration 12 can be set on the short side inner wall of the gas outlet 11. Therefore, the setting of the serration 12 can be adaptively adjusted according to the usage scenario and environmental conditions.

[0049] In this embodiment, the airflow outlet 11 has two directions: an inner side and an outer side. The inner side of the airflow outlet 11 is adapted to the microwave coaxial structure 2, while the outer side of the airflow outlet 11 directly faces the external environment. Therefore, to further enhance the excitation of the plasma torch, the height of the serrated structure 12 gradually increases and the width of the serrations 12 gradually increases along the direction from the inner side to the outer side of the airflow outlet 11. This gradual geometric shape not only achieves a natural transition from the inside to the outside but also effectively improves the stability of the airflow at the outlet. Furthermore, because the outer serrations 12 are more prominent, the airflow velocity through the outlet can be significantly increased, which is more conducive to blowing the plasma torch outward. In addition, the higher outer convex structure also forms a stronger local electric field at its tip, significantly improving the field strength distribution. The electric field and airflow field state at the serrations can be referenced. Figure 4 and Figure 5 .

[0050] like Figure 6 As shown, the microwave coaxial structure 2 in this embodiment specifically includes an inner conductor 21, an outer conductor 22, and a connector 23 for connecting to a microwave source. The outer conductor 22 is a hollow structure, and one end of the outer conductor 22 is connected to the plasma torch generating structure 1. The inner conductor 21 is installed and fixed in the internal cavity of the outer conductor 22, and the two are mechanically connected by highly insulating polytetrafluoroethylene screws to ensure that the inner conductor 21 and the outer conductor 22 are in a stable state. Both the inner conductor 21 and the outer conductor 22 are made of highly conductive metal materials to ensure low loss and high efficiency in the transmission of microwave energy. The connector 23 is located at the other end of the outer conductor 22, and both the inner conductor 21 and the outer conductor 22 are connected to the connector 23. The connector 23 can specifically adopt a standard N-type interface design, which has good impedance matching characteristics and high-frequency performance, and can easily and stably connect to an external microwave source, thereby providing the required microwave energy input for the generation of the plasma torch.

[0051] In this embodiment, the outer conductor 22 is composed of two halves connected by fasteners. This split design not only improves the ease of installation but, more importantly, effectively solves the problem that traditional one-piece structures cannot guarantee that the inner conductor 21 remains centered in the air passage. Furthermore, after prolonged operation, carbon deposits or metal oxides easily accumulate on the tip of the serrations 12, affecting conductivity and efficiency. With the two-half structure, the operator can quickly separate the outer conductor 22 to directly clean and thoroughly inspect the internal cavity and the surface of the inner conductor 21, facilitating maintenance.

[0052] like Figure 7As shown, to supply airflow to the airflow outlet 11, an annular gap is formed between the inner conductor 21 and the outer conductor 22. This gap is connected to the airflow outlet 11, thus forming a continuous airflow channel, allowing airflow to flow smoothly from the gap to the airflow outlet 11 and stably output airflow to the external environment through the airflow outlet 11. Simultaneously, to achieve gas supply, an airflow inlet 24 is constructed on the side wall of the outer conductor 22, communicating with the gap between the inner conductor 21 and the outer conductor 22. The airflow inlet 24 is located on both sides of the outer conductor 22. External airflow can enter the gap between the inner conductor 21 and the outer conductor 22 through the airflow inlet 24, then flow forward along the gap, finally reaching the airflow outlet 11, and continuously and uniformly outputting airflow to the outside through the airflow outlet 11.

[0053] It should be noted that in this embodiment, airflow inlets 24 are provided on both sides of the outer conductor 22. This solves the problem that when airflow enters from only one side, the gas flow path within the airflow channel is of varying lengths, resulting in a higher airflow velocity at the end closer to the airflow inlet 24 and a lower airflow velocity at the end farther from the inlet. Simultaneously, when the airflow enters the cavity of the outer conductor 22 from both sides, a region with a uniform airflow velocity transition can be quickly formed within the cavity. This ensures that the lateral flow velocity of the gas is basically consistent when passing through the sawtooth 12, avoiding the plasma flame from tilting due to uneven flow velocity, or even the situation where one side has a flame and the other side does not, thus ensuring the lateral consistency of the plasma torch.

[0054] In this embodiment, the plasma torch generating structure 1 and the outer conductor 22 are preferably detachably connected using fasteners. This connection method is not only simple in structure and convenient to install, but also has high connection strength and stability. Furthermore, the fasteners can be quickly disassembled to accommodate different usage scenarios or operational requirements, allowing for flexible replacement of different plasma torch generating structures 1, greatly improving the adaptability and versatility of the equipment. In addition, this design facilitates subsequent maintenance of the device and has significant practical value.

[0055] To further address the issue of uneven energy distribution encountered during the widening of microwave sources, this embodiment employs a special design for the inner conductor 21. For example... Figure 8As shown, the inner conductor 21 is generally divided into a connector end 211 and a working end 212, located at opposite ends of the inner conductor 21. The connector end 211 is mainly used to connect with the connector 23 to ensure effective microwave energy input; while the working end 212 is adapted to the plasma torch generating structure 1. The connector end 211 of the inner conductor 21 adopts a circular cross-section design to ensure compatibility with the standard coaxial connector 23 and the reliability of the connection; while the working end 212 adopts a rectangular cross-section. Through this continuous shape change from circular to rectangular, the inner conductor 21 achieves a smooth transition in aspect ratio, thereby effectively achieving continuous adjustment of impedance matching. This structural design efficiently converts microwave energy from an initially highly concentrated coaxial mode to a laterally distributed microstrip mode, improving the uniformity of energy distribution and ultimately providing the required uniform electric field for generating a wide-amplitude stable plasma torch.

[0056] To further enhance the excitation of the plasma torch, in this embodiment, the inner conductor 21 is longer than the outer conductor 22, that is, the working end 212 of the inner conductor 21 extends into the gas flow outlet 11. Preferably, the end of the working end 212 of the inner conductor 21 is flush with the outer opening of the gas flow outlet 11.

[0057] The following detailed description illustrates the specific implementation method: Based on the processing intensity and other requirements of the material to be processed, a suitable plasma torch generating structure 1 is selected and installed at the end of the outer conductor 22. During operation, working gas is introduced through the gas inlet 24, and a stable gas flow field is formed by adjusting the flow rate. Microwave energy is then fed in from the interface 23, passing through the inner conductor 21 and transforming from a coaxial mode to a wide-amplitude microstrip mode, achieving lateral energy expansion. Finally, the field enhancement effect at the tip of the sawtooth 12 breaks down the gas, and the coupling effect of the tooth gaps forms a laterally uniform plasma torch.

[0058] Example 2 The difference between this embodiment and Embodiment 1 is that in this embodiment, the length (H) and width (L) of the sawtooth 12 are 2mm. The electric field distribution at 1 mm is as follows: Figure 9 The airflow field distribution map is as follows Figure 10 .

[0059] Example 3 This embodiment provides a microwave plasma torch generating system, which includes a microwave source, an impedance matching device, a gas tank, a gas flow control unit, and the plasma torch generating device of Embodiment 1 or Embodiment 2.

[0060] The microwave power supply is connected to the connector 23 of the plasma torch generator via an impedance matching device to ensure that microwave energy can be transferred to the plasma torch generator. By precisely adjusting the output power of the microwave source and the operating state of the impedance matching device, and combining it with the flexibly replaceable plasma torch generating structure 1, the system can adapt to the operating requirements under different working conditions. It is suitable for surface modification, deep cleaning, and uniform deposition of high-quality thin films on large-area substrate materials in various atmospheric pressure environments, demonstrating excellent process adaptability and application flexibility.

[0061] In this embodiment, the gas cylinder is used to provide a continuous and stable working gas for the system. The gas cylinder can be an argon cylinder, a nitrogen cylinder, or compressed air, etc. The gas cylinder is sealed to the gas flow control unit via a pipeline. The gas flow control unit is further connected to the gas flow inlet 24 on the side wall of the plasma torch generator, forming a complete gas passage. The core of the gas flow control unit is a mass flow controller (MFC), which can precisely adjust the incoming gas flow rate according to the set value to ensure that the gas maintains a constant and suitable flow rate when flowing through the sawtooth 12. This stable gas flow condition helps to excite and maintain a transversely uniform plasma torch during the discharge process.

[0062] It should be noted that, in this embodiment, an argon gas cylinder is preferred, primarily because argon is an inert gas with a relatively simple atomic structure and metastable energy levels. Under the enhanced electric field at the tip of the serration 12, argon is more easily broken down than compressed air or nitrogen, allowing for ignition and plasma torch generation at relatively low microwave power. Furthermore, argon exhibits excellent stability at atmospheric pressure, is less prone to strong chemical reactions or dramatic thermal contraction, and can better cooperate with the serration 12 to achieve lateral energy coupling. In addition, as an inert gas, argon provides an oxygen-free environment during material processing, preventing material oxidation.

[0063] Comparative Example 1 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the serration 12 are 0.5 mm. 1mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 11 As shown.

[0064] Comparative Example 2 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the sawtooth 12 are 1 mm. 1mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 12 As shown.

[0065] Comparative Example 3 The difference between this comparative example and Example 1 or Example 2 is that the length (H) and width (L) of the serration 12 in this example are 1.5 mm. 1mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 13 As shown.

[0066] Comparative Example 4 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the sawtooth 12 are 3 mm. 1mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 14 As shown.

[0067] By measuring the electric field distribution and airflow distribution when the width of each of the 12 saw teeth is 1 mm, the following table can be obtained:

[0068] Analysis of the table above and the corresponding airflow and electric field diagrams shows that the sawtooth structure creates similar strong electric field concentration regions at multiple tips, achieving multi-point synchronous breakdown and potentially enabling uniform discharge. The sawtooth structure not only achieves high field strength at the tips but also maintains a relatively high electric field strength in non-tip regions, ensuring a uniform distribution of the field strength in the outlet area. Simultaneously, the sawtooth structure approximately doubles the airflow velocity in the outlet channel, helping to reduce plasma inhomogeneity. However, the denser the sawtooth, the lower the airflow velocity at the sawtooth points and the higher the velocity beside the inner conductor, resulting in an uneven airflow field distribution. This inhomogeneity may lead to low cooling efficiency in low-velocity regions, forming local hot spots, thereby reducing gas density and disrupting the uniformity originally achieved by the electric field design. Based on the above analysis, the optimal sawtooth length (H) and width (L) for 2mm are finally selected. 1mm.

[0069] Comparative Example 5 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the serration 12 are 0.5 mm. 0.5mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 15 As shown.

[0070] Comparative Example 6 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the sawtooth 12 are 1 mm. 0.5mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 16 As shown.

[0071] Comparative Example 7 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the sawtooth 12 are 2 mm. 0.5mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 17 As shown.

[0072] Comparative Example 8 The difference between this comparative example and Example 1 or Example 2 is that in this example, the length (H) and width (L) of the sawtooth 12 are 3 mm. 0.5mm. Its electric field distribution diagram and airflow field distribution diagram are as follows: Figure 18 As shown.

[0073] The following table can be obtained by measuring the electric field distribution and airflow distribution when the width of each sawtooth 12 is 0.5 mm:

[0074] Analysis of the table above and the corresponding airflow and electric field diagrams reveals that: When the sawtooth width decreases, the overall electric field uniformity improves slightly, but the field strength at the tip decreases significantly due to the increased distance between the tip and the inner conductor. When the sawtooth length is 1.5 mm, the electric field also exhibits a sawtooth distribution, indicating that the sawtooth tip transforms energy coupling from a single concentrated point into multiple uniformly distributed enhancement regions. This promises to enable rapid and uniform lateral expansion of the plasma after tip breakdown. Simultaneously, as the sawtooth width decreases, the cross-sectional area of ​​the outlet increases, and the overall airflow velocity decreases. The airflow field pattern is consistent with that of the 1 mm sawtooth width.

[0075] To overcome the impact of decreasing airflow velocity and achieve the transition from concentrated discharge to highly uniform planar discharge, the design must strike a balance between the influence of the electric field and the airflow field. The ultimate goal is to obtain a uniform airflow field while simultaneously maintaining multiple tip electric field enhancement regions. Based on the above analysis, the optimal length (H) and width (L) of the serration 12 are 1.5 mm. 0.5mm.

[0076] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A microwave plasma torch generator, characterized in that: It includes a microwave coaxial structure (2) and a plasma torch generating structure (1), wherein the plasma torch generating structure (1) is mounted at the end of the microwave coaxial structure (2); The plasma torch generating structure (1) is configured with an airflow outlet (11), and the inner walls of the airflow outlet (11) on both sides are configured with serrations (12). The microwave coaxial structure (2) includes an inner conductor (21) and an outer conductor (22). The inner conductor (21) is disposed inside the outer conductor (22). An airflow channel is configured between the inner conductor (21) and the outer conductor (22). The airflow channel is in communication with the airflow outlet (11).

2. The microwave plasma torch generator according to claim 1, characterized in that: The airflow outlet (11) includes an inner side and an outer side, the inner side of the airflow outlet (11) is adapted to the airflow channel, and the outer side of the airflow outlet (11) faces outward; Along the direction from the inside to the outside of the airflow outlet (11), the protrusion height of the serration (12) gradually increases and / or the width of the serration (12) gradually increases.

3. A microwave plasma torch generator according to claim 1, characterized in that: The length and width of the saw teeth (12) are 1.5 mm. 0.5mm; or; The length and width of the saw teeth (12) are 2 mm. 1mm.

4. A microwave plasma torch generator according to claim 1, characterized in that: The serrations (12) shown are provided on the long side wall of the airflow outlet (11) shown; and / or; The extension length of the sawtooth (12) is the same as the length of the airflow outlet (11); and / or; The extension width of the serration (12) is the same as the sidewall width of the airflow outlet (11); and / or; The serrations (12) shown are evenly distributed on the sidewall of the airflow outlet (11).

5. A microwave plasma torch generator according to claim 1, characterized in that: The outer conductor (22) is provided with an airflow inlet (24), which is connected to the airflow channel between the inner conductor (21) and the outer conductor (22).

6. A microwave plasma torch generator according to claim 5, characterized in that: The airflow inlet (24) is located on both sides of the outer conductor (22).

7. A microwave plasma torch generator according to claim 1, characterized in that: The inner conductor (21) includes a connector end (211) and a working end (212). The cross-section of the connector end (211) is circular, and the cross-section of the working end (212) is rectangular. The working end (212) is provided corresponding to the plasma torch generating structure (1).

8. A microwave plasma torch generator according to claim 1, characterized in that: The inner conductor (21) extends into the airflow outlet (11); and / or; The microwave coaxial structure (2) and the plasma torch generating structure (1) are detachably connected.

9. A microwave plasma torch generating system, characterized in that: It includes a microwave source, a gas source, and a microwave plasma torch generator as described in any one of claims 1 to 9, wherein both the microwave source and the gas source are connected to the microwave plasma torch generator.

10. A microwave plasma torch generating system according to claim 9, characterized in that: It also includes an impedance matching device, through which the microwave source is connected to the plasma torch generating device; and / or; It also includes a gas flow control unit, through which the gas source is connected to the microwave plasma torch generator.

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